1. Field of the Invention
The present invention generally relates to nuclear medicine and, more particularly, to systems and methods for obtaining nuclear medicine images of a patients body and/or organs of interest.
2. Description of the Background Art
Nuclear medicine is a unique medical specialty wherein radiation is used to acquire images which show the function and anatomy of organs, bones or tissues of the body. Radiopharmaceuticals are introduced into the body, either by injection or ingestion, and are attracted to specific organs, bones or tissues of interest. Such radiopharmaceuticals produce gamma photon emissions which emanate from the body. One or more detector heads are used to detect the emitted gamma photons, and the information collected from the detector head(s) is processed to calculate the position of origin of the emitted photon from the source (e.g., the body organ or tissue under study). The accumulation of a large number of emitted gamma positions allows an image of the organ or tissue under study to be displayed.
There are basically two types of imaging techniques, namely, positron emission tomography (PET) and single photon emission computed tomography (SPECT). Both PET and SPECT require gamma ray detector head(s) that calculate and store both the position of the detected gamma ray and its energy. Typically, detector head(s) include a scintillation plate which converts each received radiation event (e.g., the emitted gamma photons) into a scintillation or flash of light. An array of photomultiplier tubes positioned behind the scintillation plate and associated circuitry determine a coordinate location and a value of energy for each scintillation event.
The calibration and verification of the system is currently performed manually through the preparation and placement on the system of Tc-99m point source(s) and/or the placement of 5-20mCi Co-57 sheet source.
In that the goal of protection against undesired exposure to radioactivity is to reduce exposure to a level “as low as reasonably achievable” (ALARA), a need exists to reduce the daily exposure of the technologists to radiation relative to that received during current quality control (QC) procedures.